arc: remove "hardware.h"

This file was only required for compilation of designware_i2c driver.
Since explicit inclusion of "hardware.h" is now removed from the driver
we may safely remove this empty header as well.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

Cc: Tom Rini <trini@ti.com>
Cc: Heiko Schocher <hs@denx.de>
Cc: Stefan Roese <sr@denx.de>
Cc: Vipin Kumar <vipin.kumar@st.com>
Cc: Armando Visconti <armando.visconti@st.com>

arch/arc/include/asm/arch-arc700/hardware.h

-/*
- * Copyright (C) 2014 Synopsys, Inc. All rights reserved.
- *
- * SPDX-License-Identifier:	GPL-2.0+
- */
-
-/*
- * This file is only required to allow compilation of "designware_i2c" driver.
- * Which explicitly includes <asm/arch/hardware.h>.
- */